Overactive bladder (OAB), a syndrome defined by recurring strong urges to urinate, frequent trips to the bathroom, and in some cases involuntary urine leakage, affects up to one in five adult women and can have a profound effect on women's day-to-day activities and quality of life. Existing treatments for OAB, such as anti- cholinergic drugs, are associated with multiple side effects or have other limitations that limit their usefulness or result in high rates of discontinuation in the community. Because OAB is associated with increased levels of self-reported anxiety and perceived stress, as well as abnormalities in autonomic nervous system control that are linked with anxiety disorders, behavioral interventions that decrease anxiety and improve autonomic control offer a potentially novel approach to treating this condition. We previously examined the feasibility of teaching women with OAB symptoms to practice slow-paced respiration, a behavioral technique that involves slowing the resting breathing rate to 5 to 10 breaths per minute to improve autonomic balance. Women were assigned to practice slow-breathing exercises for approximately 15 minutes a day at home for 6 weeks using a small, commercially-available guided-breathing device that is currently FDA-approved for treatment of other conditions associated with autonomic nervous system imbalance (i.e., hypertension). In our pilot trial, recruitment of women was rapid, completion of home slow-breathing exercise sessions was high, and participants randomized to the slow-breathing intervention showed a promising trend toward reduction in OAB-related urine leakage compared to usual care. To rigorously evaluate the effects of this intervention on OAB syndrome, we propose to conduct a 12-week randomized controlled trial, in which 160 women with OAB will be randomized to: 1) use a standard guided- breathing device to practice slowing their breathing rate to 5 to 10 breaths per minute for at leas 15 minutes per day, or 2) use an identical-appearing control device that allows them to breathe at a normal rate of 14 breaths per minute. All women will complete symptom diaries and questionnaires to document OAB symptoms, undergo measures of autonomic function, and complete questionnaires about anxiety and stress. Our goals are to: 1) determine whether the proposed slow-breathing exercise program is effective in reducing the severity of OAB symptoms in women; 2) determine whether this slow-breathing intervention is effective in improving autonomic nervous system control and examine change in autonomic function as a mediator of treatment effects on OAB; and 3) determine whether this slow-breathing intervention is effective in improving anxiety symptoms and explore improvement in anxiety as a mediator of treatment effects on OAB. This study has the potential to significantly advance treatment of OAB in women, as well as change current research paradigms regarding this widely prevalent health problem.